ML20350B559

NRR E-mail Capture - Request for Additional Information Regarding Tva'S Request to Adopt Traveler TSTF-490 Deletion of E Bar Definition and Revision to RCS Specific Activity Tech Spec

ML20350B559
Person / Time
Site:	Watts Bar
Issue date:	12/15/2020
From:	Kimberly Green NRC/NRR/DORL/LPL2-2
To:	Wells R Tennessee Valley Authority
References
L-2020-LLA-0191
Download: ML20350B559 (5)

Text

From: Green, Kimberly Sent: Tuesday, December 15, 2020 6:59 AM To: Wells, Russell Douglas Cc: Shoop, Undine

Subject:

Request for Additional Information Regarding TVA's Request to Adopt Traveler TSTF-490 Deletion of E Bar Definition and Revision to RCS Specific Activity Tech Spec (EPID L-2020-LLA-0191)

Attachments: Final RAI.pdf

Dear Mr. Wells,

By letter dated August 18, 2020 (Agencywide Documents Access and Management System Accession No. ML20234A241), Tennessee Valley Authority (TVA) submitted a license amendment request (LAR) for the Watts Bar Nuclear Plant (WBN), Units 1 and 2. The proposed amendments would adopt Technical Specification Task Force (TSTF) Standard Technical Specification Change Traveler-TSTF-490, Revision 0, Deletion of E Bar Definition and Revision to RCS Specific Activity Tech Spec, and replace the current WBN, Units 1 and 2 Technical Specification 3.4.16, RCS Specific Activity, limit on reactor coolant system (RCS) gross specific activity with a new limit on RCS noble gas specific activity.

The U.S. Nuclear Regulatory Commission (NRC) staff is reviewing your submittal and has identified areas where additional information is needed to complete its review. A draft request for additional information (RAI) was previously transmitted to you by email dated December 4, 2020. You indicated that a clarification call was unnecessary. Subsequent to the transmittal of the draft RAI, TVA notified the NRC staff of an error in the numbering of STSTB RAI 1. The correct number should be STSB RAI 1.

This correction has been made in the attached RAI.

A response to the attached RAI is requested by January 22, 2021.

The NRC staff considers that timely responses to RAIs help ensure sufficient time is available for staff review and contribute toward the NRCs goal of efficient and effective use of staff resources. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-1627 or via email at Kimberly.Green@nrc.gov.

Sincerely, Kim Green (301) 415-1627 kimberly.green@nrc.gov

Hearing Identifier: NRR_DRMA Email Number: 934 Mail Envelope Properties (MN2PR09MB573942FDE33F92183C0370AA8FC60)

Subject:

Request for Additional Information Regarding TVA's Request to Adopt Traveler TSTF-490 Deletion of E Bar Definition and Revision to RCS Specific Activity Tech Spec (EPID L-2020-LLA-0191)

Sent Date: 12/15/2020 6:59:24 AM Received Date: 12/15/2020 6:59:24 AM From: Green, Kimberly Created By: Kimberly.Green@nrc.gov Recipients:

"Shoop, Undine" <Undine.Shoop@nrc.gov>

Tracking Status: None "Wells, Russell Douglas" <rdwells0@tva.gov>

Tracking Status: None Post Office: MN2PR09MB5739.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 1824 12/15/2020 6:59:24 AM Final RAI.pdf 82542 Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO ADOPT TSTF-490 WATTS BAR NUCLEAR PLANT, UNITS 1 AND 2 TENNESSEE VALLEY AUTHORITY DOCKET NOS. 50-390 AND 50-391 By letter dated August 18, 2020 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML20234A241), Tennessee Valley Authority (TVA) submitted a license amendment request (LAR) for the Watts Bar Nuclear Plant (Watts Bar), Units 1 and 2. The proposed amendments would adopt Technical Specification Task Force (TSTF) Standard Technical Specification Change Traveler TSTF-490, Revision 0, Deletion of E Bar Definition and Revision to RCS Specific Activity Tech Spec, and replace the current Watts Bar, Units 1 and 2 Technical Specification (TS) 3.4.16, RCS Specific Activity, limit on reactor coolant system (RCS) gross specific activity with a new limit on RCS noble gas specific activity.

The U.S. Nuclear Regulatory Commission (NRC) staff is reviewing the submittal and has identified the following need for additional information.

Section 50.36 of Title 10 of the Code of Federal Regulations (10 CFR) requires licensees to include TSs as part of its license and that a summary statement of the bases or reasons for such specifications be included in the application, but shall not become part of the technical specifications.

The requested TS changes appear to be consistent with Traveler TSTF-490, but the TSs and Bases are not consistent with each other making it difficult for the NRC staff to determine TVAs intent for the changes. The staff also identified that a figure that is deleted by the traveler has been previously deleted from, or not included in, the Watts Bar TSs; however, this was not included in the LAR as a variation from the Traveler. The staff identified some editorial errors in the TS Bases as well.

The following issues should be addressed to ensure that the NRC staff clearly understands the intent of the changes requested.

STSB RAI 1 The proposed note for Surveillance Requirement (SR) 3.4.16.1 requires the surveillance to be performed in Modes 1, 2, and 3 with Tavg > 500 oF. However, the markup of the note in the TS Bases says SR 3.4.16.1 is to be performed in Mode 1 only. Clarify whether the SR is to be performed in Modes 1, 2, and 3 when Tavg is greater than 500 oF or in Mode 1 only and update the TS or confirm that the appropriate changes to the TS Bases will be made to match the proposed change to the TS, as appropriate.

STSB RAI 2 The proposed SR 3.4.16.2 deletes the Note that requires the surveillance to be performed in Mode 1; however, the proposed change to the TS Bases adds a statement that says the SR

includes a note that it is to be performed in Mode 1 only. Clarify whether SR 3.4.16.2 is intended to be performed in Mode 1 only or in all Modes during which the LCO is applicable and update the TS or confirm that the appropriate changes to the TS Bases will be made to match the proposed change to the TS, as appropriate.

STSB RAI 3 Traveler TSTF-490 shows Figure 3.4.16-1 being deleted. This figure was previously deleted from the Watts Bar, Unit 1 TSs and was never part of the Unit 2 TSs. Confirm that the non-existence of this figure in each units TSs is a variation from the traveler.

STSB RAI 4 The NRC staff identified the following editorial issues in the TS Bases markup:

a. The TS Bases markup for LCO 3.4.16 includes Actions B.1 and B.2 in the heading for those Actions. However, Action B.2 is deleted in the proposed markup.

b. The TS Bases markup for Action C only includes Action C.1 in the heading. However, an Action C.2 is added in the TS markup.

c. In the TS Bases writeup for SR 3.4.16.1, it refers to SR 3.4.15.1. This appears to be an error.

Confirm that the appropriate changes to the TS Bases will be made to match the proposed changes to the TS.

ARCB RAI 1 In performing confirmatory calculations with the proposed changes to reach assurance that the doses at the exclusion area boundary(EAB) and low population zone (LPZ) remain less than 10 percent of 10 CFR Part 100 limits and that main control room (MCR) dose limits remain within the General Design Criterion 19 limit following a steam generator tube rupture accident, the NRC staff calculated doses for Unit 2 that were above the values provided in Table 15.5-19, Doses from Steam Generator Tube Ruptures, of the Watts Bar Updated Final Safety Analysis Report (ADAMS Accession No. ML20323A316).

Upon further review of the input parameters listed in Table 15.5-18, Parameters Used in Steam Generator Tube Rupture Analysis, the NRC staff confirmed that most parameters were similar between each unit except for those pertaining to the listed values for the Primary Coolant Mass Release (Flashed). Specifically, Table 15.5-18 indicates that while Unit 1 has a total primary coolant mass release of 166,200 pound-mass (lbm) and of that total a flashed mass release of 9,189 lbm, Unit 2 has a total primary coolant mass release of 191,400 lbm and a flashed mass release of 190,772 lbm.

The NRC staff notes that although the total primary coolant mass release value affects the amount of noble gases released, the portion that is flashed impacts the amount of iodines released, which greatly impacts the total dose. The amount that is flashed in Unit 2 is extraordinarily greater than the amount that is assumed to flash in Unit 1. Additionally, the staffs preliminary confirmatory calculations for the steam generator tube rupture accident show that doses at the EAB, LPZ, and MCR for Unit 2 are significantly larger than the doses for Unit 1. Although the units have different steam generators, it is unclear to the staff why there is

such a large difference in the primary coolant mass release amounts that flash directly to steam between the two units.

Explain why TVA assumes that almost the entire primary coolant mass released during a steam generator tube rupture in Unit 2 flashes directly to steam. If there is an error in the UFSAR, provide the correct values for Table 15.5-18 with references to the appropriate analyses of record.